This application relates to electronic devices and photonic devices for handling oscillation signals in a radio frequency (RF), microwave or millimeter wave spectral range.
A baseband signal can be carried by a radio frequency (RF) carrier signal to transmit either (1) wirelessly via air or (2) through a cable or waveguide from an RF signal transmitter or generator to an RF signal receiver. In many RF systems, the RF signal receiver can be designed to filter the received RF signal and to mix the filtered RF signal with an RF local oscillator (LO) signal generated by an RF local oscillator to convert the RF signal at the RF carrier frequency to an intermediate frequency (IF) at a lower frequency. The down-converted IF signal is then processed to extract the baseband signal for various signal processing operations.
In various RF applications, the RF receiver can be a tunable wideband RF receiver to tune to a range of RF frequencies. Such a wideband RF receiver can be realized using a bank of tunable RF filters to filter the received RF signal to select an RF frequency of interest from the detected input signal of an RF input port or circuit which can be, for example, a wideband RF antenna. A tunable synthesizer can be provided to mix the filtered RF signal output by the bank of tunable RF filters with the RF LO signal to down-convert the RF signal to IF. This approach requires many RF circuit elements, including the bank of filters, synthesizers, mixers, and various stages of signal amplification and thus the wideband receiver can have complex receiver circuitry and suffer losses at various stages in the circuitry. In addition, the frequency tuning range of such RF wideband receivers can be limited and narrow bandwidths can be difficult to achieve in the RF range using RF electronic filter designs.